Various electronic systems rely on batteries for the supply of power. One of the drawbacks of using batteries is their limited energy density and operational lifetime which often makes it necessary to exchange batteries on a more regular basis. Such regular exchange may be inconvenient in many applications. For example, it may be difficult to exchange batteries of remotely placed sensors that operate on battery power, such as smoke or intrusion detectors. In such applications, it is advantageous for the battery (or battery arrangement) to last as long as possible. For a fixed storage volume, it is then important in such applications to use batteries having a high energy density.
FIG. 1 shows a plot of the characteristics of specific energy, measured in Wh/kg (Watt-hours per kilogram), versus energy density, measured in Wh/1 (Watt-hours per liter) for several common battery types. As shown, out of this group of commonly available batteries, zinc/air batteries generally have the highest specific energies and energy densities, which can reach levels of more than 1000 Wh/1. Zinc/air batteries generate electrical energy from redox reactions using oxygen derived from the environment. While zinc/air batteries have high energy densities, they suffer from the drawback that they degrade quickly once the battery is exposed to the environment. The lifetime of zinc/air batteries commonly used in automotive applications, for example, may be limited to approximately 12 weeks.
In light of the useful characteristics of zinc/air batteries and their associated drawbacks, it would be advantageous to provide a zinc/air battery system and arrangement that has a longer lifetime, particularly for applications in which it is costly or inconvenient to replace depleted battery power supplies.